Available frame queue processing

Patent metadata

Field	Value
Publication number	US-10061518-B2
Application number	US-201715825404-A
Country	US
Kind code	B2
Filing date	Nov 29, 2017
Priority date	Jun 12, 2015
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

In one embodiment, a computer-implemented method includes building an available frame header queue (AFHQ). The AFHQ includes one or more headers, each header including one or more frame references being no more than a maximum count of frame references. Each of the one or more frame references of each of the one or more headers refers to an available frame. A frame request is received for one or more requested frames. One or more frame references are extracted, by a computer processor, from the AFHQ in response to the frame request. The extracting includes extracting from the AFHQ one or more requested headers including the one or more frame references referring to at least a portion of the one or more requested frames.

First claim

What is claimed is:

1. A computer-implemented method, comprising:
building an available frame header queue (AFHQ), the building the AFHQ comprising:
building one or more headers, each header comprising a queue having a plurality of frame references being no more than a maximum count of frame references, wherein each of the plurality of frame references of each of the one or more headers refers to an available frame;
defining a global header anchor comprising:
a start pointer pointing to a first header of the one or more headers in the AFHQ;
an end pointer pointing to a last header in the AFHQ; and
a maximum count variable defining the maximum count, wherein each of the one or more headers, except the last header of the AFHQ, includes a count of frame references equal to the maximum count;

receiving a frame request for one or more requested frames; and
extracting, by a computer processor, from the AFHQ one or more requested frame references in response to the frame request, wherein the frame request specifies a requested quantity for the one or more requested frames, and wherein the extracting comprises:
calculating a header quantity by taking the floor of dividing the requested quantity by the maximum count;
selecting one or more headers, the selecting comprising counting for extraction a quantity of headers equal to the header quantity in the one or more headers;
calculating a remainder quantity by taking the remainder of dividing the requested quantity by the maximum count;
determining that the reminder quantity is greater than a size of the last header in the AFHQ;
recalculating the remainder quantity as the remainder quantity less the size of the last header in the AFHQ; and
selecting, in a second-to-last header of the AFHQ, one or more frame references, the selecting the one or more frame references comprising counting for extraction a quantity of frame references equal to the recalculated remainder quantity in the second-to-last header of the AFHQ; and

returning in response to the frame request the one or more frame references, the last header of the AFHQ, and the selected one or more headers.

Assignees

• IBM

Inventors

• Hom David
• Morgenstern Harris M
• Partlow Steven M
• Tuttle Scott B
• Tzortzatos Elpida

Classifications

• G06F3/061 Primary

  Improving I/O performance · CPC title

• G06F3/0659

  Command handling arrangements, e.g. command buffers, queues, command scheduling · CPC title

• G06F3/0683

  Plurality of storage devices · CPC title